Effects of transients in LIGO suspensions on searches for gravitational waves.
M WalkerT D AbbottS M AstonG GonzálezD M MacleodJ McIverB P AbbottR AbbottC AdamsR X AdhikariS B AndersonA AnanyevaS AppertK AraiS W BallmerD BarkerB BarrL BarsottiJ BartlettI BartosJ C BatchA S BellJ BetzwieserG BillingsleyJ BirchS BiscansC BiwerC D BlairR BorkA F BrooksG CianiF ClaraS T CountrymanM J CowartD C CoyneA CummingL CunninghamK DanzmannC F Da Silva CostaE J DawD DeBraR T DeRosaR DeSalvoK L DooleyS DoravariJ C DriggersS E DwyerA EfflerT EtzelM EvansT M EvansM FactourovichH FairMolly M StevensR P FisherP FritschelV V FrolovP FuldaM FyffeJ A GiaimeK D GiardinaE GoetzR GoetzS GrasC GrayH GroteK E GushwaE K GustafsonR GustafsonE D HallG HammondJ HanksJ HansonT HardwickG M HarryM C HeintzeA W HeptonstallJ HoughK IzumiR JonesS KandhasamyS KarkiM KasprzackS KauferK KawabeN KijbunchooE J KingP J KingJ S KisselW Z KorthG KuehnM LandryB LantzN A LockerbieM LormandA P LundgrenM MacInnisS MárkaZ MárkaA S MarkosyanE MarosI W MartinD V MartynovK MasonT J MassingerF MatichardN MavalvalaR McCarthyD E McClellandS McCormickG McIntyreG MendellE L MerilhP M MeyersJ MillerR MittlemanG MorenoG MuellerA MullaveyJ MunchL K NuttallJ OberlingM OliverP OppermannRichard J OramB O'ReillyD J OttawayH OvermierJ R PalamosH R ParisW ParkerA PeleS PennM PhelpsV PierroI PintoM PrincipeL G ProkhorovO PunckenV QuetschkeE A QuinteroF J RaabH RadkinsP RaffaiS ReidD H ReitzeN A RobertsonJ G RollinsV J RomaJ H RomieS RowanK RyanT SadeckiE J SanchezV SandbergR L SavageR M S SchofieldD SellersD A ShaddockT J ShafferB ShapiroP ShawhanD H ShoemakerD SiggB J J SlagmolenB SmithJ R SmithB SorazuA StaleyK A StrainD B TannerR TaylorM ThomasP ThomasK A ThorneE ThraneC I TorrieG TraylorD TuyenbayevG VajenteG ValdesA A van VeggelA VecchioP J VeitchK VenkateswaraT VoC VorvickR L WardJ WarnerB WeaverR WeissP WeßelsB WillkeC C WipfJ WordenG WuH YamamotoC C YanceyHang YuHaocun YuL ZhangM E ZuckerJ ZweizigPublished in: The Review of scientific instruments (2018)
This paper presents an analysis of the transient behavior of the Advanced LIGO (Laser Interferometer Gravitational-wave Observatory) suspensions used to seismically isolate the optics. We have characterized the transients in the longitudinal motion of the quadruple suspensions during Advanced LIGO's first observing run. Propagation of transients between stages is consistent with modeled transfer functions, such that transient motion originating at the top of the suspension chain is significantly reduced in amplitude at the test mass. We find that there are transients seen by the longitudinal motion monitors of quadruple suspensions, but they are not significantly correlated with transient motion above the noise floor in the gravitational wave strain data, and therefore do not present a dominant source of background noise in the searches for transient gravitational wave signals. Using the suspension transfer functions, we compared the transients in a week of gravitational wave strain data with transients from a quadruple suspension. Of the strain transients between 10 and 60 Hz, 84% are loud enough that they would have appeared above the sensor noise in the top stage quadruple suspension monitors if they had originated at that stage at the same frequencies. We find no significant temporal correlation with the suspension transients in that stage, so we can rule out suspension motion originating at the top stage as the cause of those transients. However, only 3.2% of the gravitational wave strain transients are loud enough that they would have been seen by the second stage suspension sensors, and none of them are above the sensor noise levels of the penultimate stage. Therefore, we cannot eliminate the possibility of transient noise in the detectors originating in the intermediate stages of the suspension below the sensing noise.